The clinical evolution of patients with idiopathic spinal cord herniation: a case series.

Study design: Retrospective case series of 48 patients.

Objectives: This study's primary objective was to provide a clinical description of a group of individuals with a working diagnosis of idiopathic spinal cord herniation (ISCH). The secondary objectives were to appreciate the natural history of these patients and describe their clinical evolution with conservative or surgical management.

Setting: The study was carried out at l'Hôpital de l'Enfant-Jésus, CHU de Québec (Québec, Canada), a tertiary care university hospital.

Methods: This case series study is based on routinely collected data. Forty-eight (48) cases were identified as having an ISCH on MR imaging, between 2009 and 2019. Their medical files have been searched retrospectively. Patient characteristics were described according to their asymptomatic or symptomatic status.

Results: The mean age of patients at the time of diagnosis was 52.5 years. Most of the patients identified were asymptomatic (69%) and followed clinically. The main neurologic presentation for the symptomatic group was Brown-Séquard-like syndrome. 20% of the symptomatic patients were rapidly treated surgically after consultation with the neurosurgeon. The mean follow-up duration was 56 months for asymptomatic patients and 51 months for symptomatic patients. Most of our patients (41 out of 45) were considered stable or unchanged at follow-up. There was no neurological progression in all asymptomatic patients.

Conclusions: Our study shows that ISCH and its variants are not always symptomatic and may be a fortuitous finding. As the natural history may be non-progressive, it is probably appropriate to treat some cases expectantly.